Gemstone Necklaces

Which stones give which color

The color filter is the easiest way into this grid. Each color comes from more than one gem, and they behave differently.

• Blue comes from sapphire, aquamarine and tanzanite. Sapphire gives the deepest, most durable blue. aquamarine a pale sky blue. tanzanite a blue with violet flashes.
• Green comes from emerald, tourmaline and peridot. Emerald is the most valuable green. tourmaline and peridot are cleaner and cost less.
• Red comes from ruby, spinel and garnet. Ruby prices highest, with spinel the red most often mistaken for it.
• Purple comes from amethyst and tanzanite.

Choose the color that appeals to your eye first, then compare stones within it.

Why a pendant opens up the softer stones

Hardness decides what a stone can survive on a finger. At the throat it matters far less.

Ruby and sapphire sit at 9 on the Mohs scale and emerald at 7.5 to 8. Tanzanite and peridot sit nearer 6.5, which is a real concern in a ring and a minor one in a pendant that rarely takes a knock.

That makes a necklace the best place for a stone you love that would not suit daily wear on a hand. Remove it before the gym, and keep tanzanite and emerald out of ultrasonic cleaners.

Precious against semi-precious, in value terms

• Ruby, sapphire and emerald carry origin premiums, laboratory origin opinions and a real market for top stones.
• Spinel and tanzanite sit in between. Tanzanite is mined in a single area in Tanzania, so its supply depends on one source.
• Aquamarine, tourmaline, amethyst, citrine, peridot and garnet give size and color for far less, and are best bought for how they look to you.

Metal and style

White gold and platinum keep blues and greens crisp. Yellow gold warms reds and purples. Rose gold flatters pink tones and softens pale stones.

Solitaires show the most stone, halos make a modest stone read larger, and drop designs suit pear and oval shapes. There is also a men's selection, generally heavier in the chain and lower in the setting.